The Royal Alcazarof Seville is one of the most representative monumental compounds in the city of Seville. It is a Moorish fort built in the 10th century by the Arabs during the time of the Moorish invasion. Later, it has been expanded by the Spanish Kings who converted it into their royal residences. In 1987 it was declared by UNESCO as a World Heritage Site, along with the Seville Cathedral. The Alcázar is a great example of Mudejar architectural style in Spain, although Islamic, Gothic, Renaissance and Baroque elements can be found. It's characterized by being a mixture between Muslim and Christian elements, resulting in a unique design that can be found only in Spain.